"Billy Don't Be a Hero" is a 1974 pop song that was first a UK hit for Paper Lace and then, some months later, a US hit for Bo Donaldson and The Heywoods. The song was written and composed by two British songwriters, Mitch Murray and Peter Callander.
Because the song was released in 1974, it was associated by some listeners with the Vietnam War, though the war to which it actually refers is never identified in the lyrics. It has been suggested that the drum pattern, references to a marching band leading soldiers in blue, and "riding out" (cavalry) refer to the American Civil War. However the drum beat and cavalry "riding out" is not specific to the American Civil War, and blue uniforms were common in the 19th century. For one of the band's performances on Top of the Pops they wore Union-style uniforms, as can be seen on YouTube.
A young woman is distraught that her fiancÚ chooses to enlist with Army recruiters passing through the town, causing her to implore him:
Billy, don't be a hero, Come back and make me your wife
And as he started to go, she said, 'Billy keep your head low'
Billy, don't be a hero, Come back to me.
The song goes on to describe how Billy is killed in action in a pitched battle after volunteering to ride out and seek reinforcements. (This suggests mounted infantry and a lack of modern two-way radio communications.) In the end, the heartbroken woman throws away the official letter notifying her of Billy's "heroic" death.